Fuel control system



March 15, 1966 w. A. RAY 3,240,257

FUEL CONTROL SYSTEM Filed April 11, 1963 2 Sheets-Sheet 1 INVENTOR.WiLUAM A. RAY

ATTORNEYS.

March 15, 1966 w. A. RAY 3,240,257

FUEL CONTROL SYSTEM Filed April 11, 1963 2 Sheets-Sheet 2 WILUAM A. RAY

ATTOYZ N EYS.

United States Patent 3,240,257 FUEL CGNTROL SYSTEM William A. Ray, NorthHollywood, Calif, assignor, by

mesne assignments, to International Telephone and Telegraph Corporation,New York, N.Y., a corporation of R'laryland Filed Apr. 11, 1963, Ser.No. 272,406 2 Claims. (Cl. 158-125) The present invention relates tofuel control systems for controlling the safe burning of gas at a mainburner.

Briefly, the system described herein involves a main gas burner, a pilotburner for igniting gas from the main burner, control apparatusfunctioning to operate to sup-ply gas to the main burner only when thereis a pilot flame at the pilot burner. The pilot flame is established byelectric ignition.

One feature of the system is that closure of a switch results in anautomatic interlocked sequence of events wherein the pilot flame isfirst established by electric ignition, after which, with some timedelay, the previously mentioned control apparatus functionsautomatically to allow gas flow to the main burner.

In one form of the invention the control apparatus involves athermocouple heated by the pilot flame and in a second form of theinvention the control means involves the heating of a mercury-filledbulb. In both forms of the invention, gas flow to the main burner isthrough two series-connected valves, the first or upstream valve beingelectrically operated substantially simultaneously with the electricaligniting means for supplying gas to the pilot burner, while the secondor downstream valve is opened automatically only when a safe pilot flamehas been established and only after some time delay during which thethermocouple or mercury bulb, as the case may be, is heated sufficientlyto cause operation of such second or downstream valve.

It is therefore a general object of the present invention to provide afuel system of the character described.

A specific object of the present invention is to provide a fuel systemof this character wherein, in the shutdown condition of the system, gasis prevented from flowing both to the pilot and main burners.

Another specific object of the present invention is to provide a systemof this character in which operation of a switch results automaticallyin establishment of a pilot flame followed, with some time delay, byestablishment of the main burner flame.

Another specific object of the present invention is to provide a systemof this character which incorporates a thermocouple heated by a pilotflame.

Another specific object of the present invention is to provide a systemof this character incorporating a mercury bulb heated by the pilotflame.

Another object of the present invention is to provide a system of thischaracter in which there is proper interlocking to assure theaboveindicated safe sequence of events.

The features of the present invention which are believed to be novel areset forth with particularity in the appended claims. This inventionitself, both as to its organization and manner of operation, togetherwith further objects and advantages thereof, may be best understood byreference to the following description taken in connection with theaccompanying drawings in which:

FIGURE 1 illustrates a system embodying features of the presentinvention using a mercury bulb.

FIGURE 2 illustrates a system embodying features of the presentinvention using a thermocouple.

Referring to FIGURE 1, the same includes a main burner 10, a pilotburner 12 mounted in close proximity to the main burner for igniting gasflowing from the main burner, a spark igniter 14 mounted in closeproximity to the pilot burner 12 for igniting gas flowing therefrom toestablish the pilot flame, a mercury-filled capillary bulb 16 mounted inclose proximity to the pilot burner 12 :so as to be heated thereby forperforming a control operation as described later.

The main burner 10 is in communication with the outlet opening 18 ofvalve casing 20 via main burner line 22. Gas is supplied to such casing20 through its inlet opening 24 and gas can flow to the main burner 10only when the two series-connected valves 26 and 28 are open, the valve26 being referred to as the first or upstream valve and beingelectrically operated and the valve 28 being referred to as the secondor downstream valve and being operated in accordance with the heatedcondition of the mercury bulb 16.

The pilot burner 12 is connected via the pilot burner line 30 to anopening 32 in casing 20 at a location between valves 26 and 28 such thatgas may flow to the pilot burner 12 when the electrically operated valve26 is open and regardless of the open or closed position of thedownstream valve 28.

The valves 26 and 28 are normally closed, the Valve 26 being closed bycoil compression spring 34 which acts between the valve closure member36 on diaphragm 38 and a stationary portion of the magnetic coil andcore structure 40 that includes coil 42 to thereby normally press themovable closure member 36 against the annular valve seat 44.

The valve 28 is normally closed (unheated condition of the mercury bulb16) by coil compression spring 46 acting between a closure member 48 forcasing 20 and an intermediate portion of lever 5t) which has one of itsends fulcrumed on a stationary support member 52 and which has its otherend mounting a valve closure member 54 seatable on the annular valveseat 56. A supplementary biasing spring 58, weaker than spring 46, maybe interposed between the closure member 54 and the casing 20 forassuring proper operation of the valve 28, it being noted that theclosure member 54 is loosely mounted on lever 50.

The igniter 14, in the nature of a spark plug, is connected to thesecondary winding 60 of ignition transformer 62 via a high tensionshielded cable 64 which has its outer metal sheath grounded and itsinner conductor connected in series with a stabilizing resistance 66,the resistance 66 being shielded also by the outer metal sheath. Thetransformer is so designed that without a load on the secondary, throughenergization of the igniter 14, insufficient current will flow throughthe primary circuit to maintain the solenoid valve 40 in open position.

The primary winding 68, comprising two series-connected sections 68A and68B, is connected in series with a capacitor 70, a voltage source 72, aswitch 74 and the operating coil 42 for valve 26.

In the following description of the operation of the system shown inFIGURE 1, it is assumed that initially the switch 74 is open and themercury bulb 16 is in an unheated condition, in which case both valves26 and 28 are closed. The system is placed in operation by closingswitch 74 and such closure results substantially simultaneously inestablishment of a spark at igniter 14 and the flow of pilot gas to thepilot burner 12 which is ignited by the spark to establish the pilotflame. The pilot flame heats the mercury bulb 16 to accomplish anexpansion of the mercury in the capillary tubing 17 and this expandingforce of the mercury is transmitted to the lever 50 which then moves ina clockwise direction in FIGURE 1 against the action of its biasingspring 46 to open the valve 28 and allow gas to flow to the main burner10 where it is ignited by the pilot flame.

The system shown in FIGURE 2 includes parts which are identical withthose in FIGURE 1 and for that reason such parts have identicalreference numerals in both FIGURES 1 and 2. Essential differencesbetween FIG- URES 1 and 2 involve the use of a thermocouple 116 insteadof the mercury bulb 16 and a pressure-responsive valve 128 in FIGURE 2is used instead of the mercuryoperated valve 28 in FIGURE 1.

The thermocouple 116 is connected to a coil 200 wound on a generallyU-shaped core member 202 and serves to control a three-way valve 204having ports 206 and 208, these ports 206 and 208 being closable by aflapper element 210 which serves not only as a valve element but also asan armature attractable by the core member 202. For this purpose thearmature element 210 is pivoted on one end of the U-shaped core member202 and is normally urged into closed position against the port 208 bythe coil compression spring 212.

The valve 128 comprises a closure member 214 mounted on a diaphragm 216,the closure 214 being seatable on the annular valve seat 216A. It willbe seen that the diaphragm 216 defines walls of two different gaschambers, namely a first upper gas chamber 220, which is incommunication with the valve seat 44, and a second lower sealed chamber222 within which the threeway valve 204 is mounted.

The chamber 220 is constantly in communication with the pilot burnerline 30 through a path which includes: a passageway 224, channel 226within which a pilot adjustment valve 228 is located, and the outletconnection 230, such passageway, channel and connection being formed inthe wall of casing 20. Thus, when valve 26 is open, gas flows to thepilot burner 12 regardless of the condition of valve 128.

Chamber 220 is also in communication with the pilot port 206 through apassageway 232 in the valve casing. The other valve port 208 is incommunication with the previously mentioned pilot outlet connection 230through a passageway 234 in the wall casing.

The following described operation of the system shown in FIGURE 2assumes initially that the switch 74 is open and the thermocouple 116 isin an unheated condition, and in such case both valves 26 and 128 areclosed and port 7 208 is closed by the spring-pressed armature flapper210.

Also, under this condition, chambers 220 and 222 are in communicationwith each other through the open port 206 so that the pressure onopposite sides of the dia phragm 216 are balanced, thus assuring aclosed condition of the valve 128, such closure being further assured bythe coil compression spring 240 acting between the diaphragm 216 and astationary part of the pilot valve 204.

The system of FIGURE 2 is started in operation by closing switch 74,such closure resulting in energization of the coil 42 and opening ofvalve 26 and also the development of an ignition spark at the sparkigniter 14. This opening of valve 26 results in flow of pilot gas fromchamher 220 and passageway 224 and pilot connection 230 to the pilotburner where such gas is ignited by the ignition spark. At thisparticular time the valve 128 remains closed, since the pressure actingon the topside of diaphragm 216 is equal to the pressure acting on theunderside of diaphragm 216, the pressure to the underside beingcommunicated through passageway 232 and port 206. The pilot flame thenheats the thermocouple 116 which develops sufficient current, after atime delay required to heat the thermocouple, to cause the armature 210to be moved to its other position wherein the port 206 is now close andh p 208 i qp T p i g t port 208 results in venting of the previouslyapplied gas pressure in chamber 222 to the pilot line 30 via passageway234 and connection 230 so that gas then escaping from chamber 222 isburned at the pilot burner. This reduction in pressure in the chamber222 results in unbalanced forces on the diaphragm 216 with the resultthat the pressure in the upper chamber 220 is effective to move thediaphragm 216 and the closure member 214 thereon downwardly to open thevalve 128 and allow the flow of gas to the main burner where it isignited by the pilot flame.

While the particular embodiments of the present invention have beenshown and described, it will be obvious to those skilled in the art thatchanges and modifications may be made without departing from thisinvention in its broader aspects and, therefore, the aim in the appendedclaims is to cover all such changes and modifications as fall within thetrue spirit and scop of this invention.

1. In a fluid control system; a valve structure having a first valvemeans interconnected with a pilot burner and having a serially relatedsecond valve means interconnected with a main burner positioned adjacentsaid pilot burner; a first actuator system for selectively operating thesaid first valve means and a second actuator system for operating thesaid second valve means responsive to the said operation of the saidfirst valve means; the said first actuator system comprising fuelignition means positioned adjacent the said pilot burner,electromagnetic means associated with said first valve means, andswitch-controlled circuitry including a power source for simultaneouslyoperating said electromagnetic means and said gas ignition means inmutual dependence on each other; and means included in said switchcontrolled circuitry for insuring that a failure of said ignition meansdisables said electromagnetic means; the said second actuator systemcomprising thermo-responsive means positioned adjacent the said pilotburner and mechanical operator means positioned adjacent the said secondvalve means, with operation of said mechanical operator means beingcontrolled solely by said thermo-responsive means independent of saidpower source; and the said operation of said first valve means by thesaid switch-controlled circuitry permitting the passage of fuel from aninlet on said valve structure through said first valve means to saidpilot burner where it is ignited by said fuel ignition system andenergizes said thermo-responsive device to operate sa-id mechanicalmeans permitting the passage of fuel from said inlet through said firstand second serially related valve means to said main burner where it isignited by said ignited pilot burner fuel.

2. A fluid control system as set forth in claim 1 wherein said powersupply comprises an alternating current source for generating acontinuous open-gap arcing of said fuel ignition means and wherein saidthermo-responsive means includes an expansible fluid reacting withflexible diaphragm positioned in direct mechanical contact with the saidmechanical means.

References Cited by the Examiner UNITED STATES PATENTS 2,797,909 7/1957Rulseh 158-123 X 2,939,523 6/1960 Ray 15813l 3,062,276 11/1962 Miller etal 158124 FREDERICK L. MATTESON, JR., Primary Examiner.

MEYER PERLIN, JAMES w. WESTHAVER,

Ex er

1. IN A FLUID CONTROL SYSTEM; A VALVE STRUCTURE HAVING A FIRST VALVE MEANS INTERCONNECTED WITH A PILOT BURNER AND HAVING A SERIALLY RELATED SECOND VALVE MEANS INTERCONNECTED WITH A MAIN BURNER POSITIONED ADJACENT SAID PILOT BURNER; A FIRST ACTUATOR SYSTEM FOR SELECTIVELY OPERATING THE SAID FIRST VALVE MEANS AND A SECOND ACTUATOR SYSTEM FOR OPERATING THE SAID SECOND VALVE MEANS RESPONSIVE TO THE SAID OPERATION OF THE SAID FIRST VALVE MEANS; THE SAID FIRST ACTUATOR SYSTEM COMPRISING FUEL IGNITION MEANS POSITIONED ADJACENT THE SAID PILOT BURNER, ELECTROMAGNETIC MEANS AS SOCIATED WITH SAID FIRST VALVE MEANS, AND SWITCH-CONTROLLED CIRCUITRY INCLUDING A POWER SOURCE FOR SIMULTANEOUSLY OPERATING SAID ELECTROMAGNETIC MEANS AND SAID GAS IGNITION MEANS IN MUTUAL DEPENDENCE ON EACH OTHER; AND MEANS INCLUDED IN SAID SWITCH CONTROLLED CIRCUITRY FOR INSURING THAT A FAILURE OF SAID IGNITION MEANS DISABLES SAID ELECTROMAGNETIC MEANS; THE SAID SECOND ACTUATOR SYSTEM COMPRISING THERMO-RESPONSIVE MEANS POSITIONED ADJACENT THE SAID PILOT BURNER AND MECHANICAL OPERATOR MEANS POSITIONED ADJACENT THE SAID SECOND VAVLE MEANS, WITH OPERATION OF SAID MECHANICAL OPERATOR MEANS BEING CONTROLLED SOLELY BY SAID THERMO-RESPONSIVE MEANS INDEPENDENT OF SAID POWER SOURCE; AND THE SAID OPERATION OF SAID FIRST VALVE MEANS BY THE SAID SWITCH-CONTROLLED CIRCUITRY PERMITTING THE PASSAGE OF FUEL FROM AN INLET ON SAID VALVE STRUCTURE THROUGH SAID FIRST VALVE MEANS TO SAID PILOT BURNER WHERE IT IS IGNITED BY SAID FUEL IGNITION SYSTEM AND ENERGIZES SAID THERMO-RESPONSIVE DEVICE TO OPERATE SAID MECHANICAL MEANS PERMITTING THE PASSAGE OF FUEL FROM SAID INLET THROUGH SAID FIRST AND SECOND SERIALLY RELATED VALVE MEANS TO SAID MAIN BURNER WHERE IT IS IGNITED BY SAID IGNITED PILOT BURNER FUEL. 